Mounting device for an electrical circuit element



Jan. 14, 1947. o. M. DUNNING MOUNTING DEVICE FOR AN ELECTRICAL CIRCUIT ELEMENT Filed Sept. 15, 1943 FIG.3

INVENTOR ORVILL mouum 6 RNEY 2 Patented J... 14, i947 MOUNTING DEVICE FOR AN. ELECTRICAL CIRCUIT ELEMENT Orville M. Dunning, Great Neck, N.

by mesne assignments, to Hazeltine Research, Inc., Chicago, 111., a corporation of Illinois Y., assignor,

Application September 15, 1943, Serial No. 502,511 Claims. (Cl. 173-324) This invention relates to a device for mounting an electrical circuit element on a supporting structure of a high-frequency circuit.

In constructing radio-frequency apparatus, such as commercial broadcast receivers, it is conventional practice to secure one or more insulated mounting strips to the chassis thereof for the purpose of mounting small electrical circuit elements in an orderly manner. nals usually arranged in pairs on such mounting strips permit mounting resistors, condensers, radio-frequency chokes and similar circuit elements thereon by soldering the leads of the circuit elements to selected ones ofthe terminal pairs. Further, these terminals receive additional or extra leads through which the circuit elements arranged on the individual mounting strips are electrically connected in the circuit of the particular apparatus. It will be apparent that the extra leads to and from such terminals may have an appreciable length but, since the leads may be grouped in cables and fastened to the chassis through simple cable clamps, this feature is not undesirable in broadcast radiofrequency equipment, where such a mounting arrangement is generally satisfactory.

With the advent of apparatus operating on frequencies above the broadcast range, and particularly apparatus having an operating frequency in the ultra-high-frequency range, the construction techniques developed through long experience in the broadest field were found to be completely unsatisfactory in many cases. Thus, when mounting arrangements of the. aforedescribed type are utilized in the construction of such ultra-high-frequency equipment, it is found that the distributed circuit constants of leads, which are largely ineffective at broadcast frequencies, contribute greatly to the operating characteristics of the circuit. For this reason, the described prior art arrangements, which generally require the use of extra leads of an appreciable and indeterminate length, are not suited for wide application in such high-frequency apparatus operating beyond the broadcast range.

It is, therefore, an object of the invention to provide a device especially suited for mounting an electrical circuit element on a supporting structure of a high-frequency circuit and which avoids the aforementioned limitations of prior art arrangements.

It is another object of the invention to provide an improved device for mounting an electrical circuit element on a supporting structure of a high-frequency circuit which substantially reduces the lengths of leads required electrically to connect an element mounted therein to its asso- Electrical termiciated circuit.

It is another object of the invention to provide an improved device for mounting an electrical circuit element on a supporting structure of a high-frequency circuit which has a simple, compact and inexpensive construction.

In accordance with the invention, a device for mounting an electrical circuit element, having oppositely extending substantially coaxial conductive terminal leads, on a supporting structure of a high-frequency circuit comprises: a single socket of conductive material for receiving the element, the socket being proportioned to support the element throughout a substantial portion of its length; and an integral conductive projection extending from a small peripheral portion of the socket and having a flange portion provided with an aperture substantially coaxial with the socket. The device includes a conductive mounting means secured to the flange portion for mounting the socket on a supporting structure in a predetermined spaced relation thereto and having a longitudinally extending internal bore, in substantially coaxial alignment with the aperture of the flange and with the socket, to receive one of the coaxial leads of the circuit element.

For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Fig. 1 of the drawing is a perspective view of a device, in accordance with the invention, for mounting an electrical circuit element on a supporting structure; Fig. 215 a cross-sectional view of the device taken along sectional line AA of Fig. 1, showing an electrical circuit element supported thereby in spaced relation on a supporting structure; and Fig. 3 is an additional cross-sectional view of the device taken along the sectional line 8-3 of Fig. 2.

Referring now to the drawing, a device in accordance with a, preferred embodiment of the invention for mounting an electrical circuit element on a supporting structure of a high-frequency circuit comprises a single socket I 0 for receiving the element. The socket consists of a formed band of resilient and conductive material proportioned to support the element throughout at least a substantial portion of its length. This band preferably comprises a strip of brass, silvertion on supporting structures.

the drawing. Of these, lead L1 is internally con nected to the case and is brought out for connection to a suitable ground terminal, while lead L2 is connected to the ungrounded terminal of the condenser and is insulated from the case. Such condensers are of a generally cylindrical configuration so that for the instant application socket to has the form of a split elongated cylinder. The internal diameter of. the cylinder corresponds'substantially to the diameter of condenser C and its longitudinal axis has a length equal to at least one-half that of the condenser.

By proportioning the socket as indicated, the electrical element is supported throughout a sub stantial portion of its length,- providing a mechanically rugged arrangement even though the element, per se, may be fragile, as is often the case.

One end of socket ID has a flared opening, to facilitate inserting the condenser, as indicated at H and I2. An integral projection l3 extends from the opposite end of the-socket and has a flange portion [-4 including provisionsfor mounting the socket in a predetermined spaced rela- The angular relation between flange portion I4 and the longitudinal axis of socket I determines the spaced portion l4. Additionally, an electrical connection with the element mounted in socket I0 is available through the internal bore of mounting member l5. Such connection may be insulated from the mounting device II] by means of a sleeve 2| of any suitable insulating material, .such as a polyvinyl resin, projecting through and beyond flange portion 14 and mounting member l5.

In utilizing the described device to mount an electricalcircuit element, such as by-pass condenser C, in a predetermined spaced relation on a supporting structure S or chassis of a highfrequency circuit, the supporting structure is punched to provide an aperture having a diameter' slightly larger than that of mounting member.l5 and to provide a tab S slightly narrower than the keyway of skirt l6 and projectin'gout' of the plane of the supporting structure. Mounting member [5 is thereafter inserted into the aperture and oriented so that tab S is received by the keyway of skirt l6. Nut 18 is then threaded upon member l5 and tightened to secure the mounting device in position and to force tab S into full engagement with keyway ll, thereby locking socket 10 against rotation. Con denser C may now be inserted into socket I0 and connected into the circuit of the particular apparatus.

In the usual case the supporting structure S of the high-frequency circuit serves as a ground plate and one terminalof condenser C may be relation between the socket and its associated supporting structure. Where it is desired to have the socket substantially perpendicular to the supporting structure, flange portion I4 is disposed substantially transversely of the longitudinal axis of the socket, as illustrated in the drawing.

Flange portion [4 is provided with an aperture through which the described device may be riveted, soldered, or otherwise secured on asupport- .ing structure. However, in the preferred embodiment a. hollow externally threaded mounting member is utilized in mounting the device. Such member may comprise .a screw l5 of silverplated brass having an internal bore and a reduced section adapted to be received by the aperture in flange portion 14. A skirt or flange I5 is formed integrally with -member 15 and includes a'keyway l1, Fig. 3, constituting means for engaging a supporting structure to lock the socket l0 against rotation. In assembling member l5 to the mounting device, its reduced section is inserted into the aperture provided in the flange portion l4 and spun over. This construction, for the arrangement under consideration,

: causes the aperture in flange portion l4 and-the through insulated sleeve 2| for direct connection with a circuit component (notshown) and its lead L1 is soldered to lug l9. On the other hand, when the ungrounded terminal of condenser C is to ,be connected with a circuit component positioned on the same side of chassis S as the mounting device, the condenser is mounted in the socket-l0 in the opposite direction so that lead L1 will be soldered to terminal lug 20 and lead L2 will connect directly with the other circuit component. In either case, a low-impedance circuit to ground is provided even for the highfrequency signals involved. This .results from the fact that the grounded lead L1 is extremely short, that it is shunted by the directconnection between'the condenser case and socket"), and also from the fact that the socket itself by its configuration presents a very low-impedance path to ground plate S.

For the described application, in which the mounting device is used to support a metal-cased condenser of the type having one terminal connected to the case, the lead inductance is redenser terminals, as well as condensers having no metal casing, such as ceramic condensers, may likewise be advantageously mounted with the described structure. In each instance, the lead lengths may be reduced to a minimum and the tions it is only necessary to form and proportion socket ID in thedescribed manner so as to support the circuit element throughout a substantial portion of its length. In these applications, the electrostatic shielding afforded by the mounting arrangement may be of considerable value.

when mounting a resistance element in the described device, there is the additional advantage that the mounting device. by'having good thermal conductivity and by gripping a substan tial porton of the resistor, provides an increased radiation surface. Through this eflect, the operating temperature of the resistor is materially reduced, permitting additional dissipation or producing a'greater safety factor if such additional dissipation is not utilized.

Several other important advantages of the described mounting device over the aforementioned mounting strips of the prior art will be readily apparent. For example, the described device may support a circuit element in such relation to the circuit in which it is to be incorporated that the lengths of its leads L1 and 1a are reduced to a fixed and absolute minimum value and no extra leads are required for connecting the element into the particular circuit. Also. the mounting device permits a circuit element supported therein to be connected easily with other circuit elements positioned on either side of the circuit-supporting structure S. Furthermore. such a device enables any number of out at least a substantial portion of its. length:

. portion for mounting said socket on a supporting circuit elements to be added substantially at will in a high-frequency circ'uit, whereas a conventional mounting strip is able to accommodate only a predetermined number of circuit elements.

It will-be understood that the described arrangement comprises a preferred, but not exclusive, embodiment of the invention. For example, socket 10 may, if desired, be a screwtypesocket and it need not necessarily be of resilient and conductive material. Also, flange portion It may have any desired angular relationship with reference to the longitudinal axis of socket It. For certain applications, it may be arranged substantially parallel thereto for the purpose of supporting a circuit element in parallel relationship to a supporting structure.

Likewise, mounting member [5 is subject to a wide range of modifications. In accordance withone modification, member l5 may comprise a standard machine screw soldered to flange portion It. When so modified, the mounting device may be secured to supporting structure S by providing therein a tapped hole tobe engaged by the mounting screw. With such an arrangement,

the screw provides means for adjustably mountelement, having oppositely extending substantialiy coaxial conductive terminal leads, on a supporting structure of a high-frequency circuit comprising: a single socket of conductive material for receiving said element, said socket being proportioned to support said element throughstructure in a predetermined spaced relation thereto and having a longitudinally extending internal bore, in substantially coaxial alignment with said aperture of said flange and with said socket, to receive one of said coaxial leads.

2. A device for mounting an electrical circuit element, having oppositely extending substantially coaxial conductive terminal leads, on a supporting structure of a high-frequency circuit comprising: a single socket of conductive materialior receiving said element, said socket being proportioned to support said element throughout at least a substantial portion of its length; an integral conductive projection extending from a small peripheral portion of said socket and having a flange portion provided with an aperture substantially coaxial with said socket; conductive mounting means secured to said flange portion for mounting said socket on a supporting structure in a predetermined spaced relation thereto and having a longitudinally extending internal bore, in substantially coaxial alignment with said aperture of said flange and with said socket, to receive one of said coaxial leads; and a sleeve of insulating material disposed within said bore of said mounting means to provide an insulated channel therethrough.

3. A device for mounting an electrical circuit element, having oppositely extending substantially coaxial conductive terminal leads, on a supporting structure of a high-frequency circuit comprising: a single socket of conductive material ior receiving said element, said socket having an electrical terminal formed at one end thereof and being proportioned to support said element throughout at least a substantial portion of its length; an integral conductive projection extending from a small peripheral portion 0! the opposite end of said socket and having a flange portion provided with an aperture substantially coaxial with said socket; conductive mounting means secured to said flange portion for mounting said socket on a supporting structure in a predetermined spaced relation thereto and having a longitudinally extending internal 'bore, in substantially coaxial alignment with said aperture of said flange and with said socket, to receive one of said coaxial leads; and a second electrical terminal supported by said mounting means in the vicinity of said opposite end of said socket.

4. A device for mounting an electrical circuit element, having oppositely extending substantially coaxial conductive terminal leads, on a supporting structure of a high-frequency circuit comprising: a single socket of conductive material for receiving said element, said socket being proportioned to support said element throughout at least a substantial portion of its length; an integral conductive projection extending from a small peripheral portion of said socket and having a flange portion provided with an aperture substantially coaxial with said socket; and a hollow externally threaded conductive mounting member secured to said flange portion in substantially coaxial alignment with said aperture thereof for mounting said socket on a supporting structure in a predetermined spaced relation thereto, said mounting means being adapted to receive one of said coaxial leads through the hollow interior thereof.

5. A device for mounting an electrical circuit element, having oppositely extending substantially coaxial conductive terminal leads,-on a supporting structure of a high-frequency circuit comprising: a single cylindrical socket of resilient and conductive material having'a flared opening at one end for receiving said element. 10

said socket being proportioned to support said element throughout at least a substantial portion of its length; an integral conductive projection extending-from a small peripheral portion of the opposite end of said socket and having a flange portion provided with an aperture substantially coaxial with said socket; and conductive mounting means secured to said flange portion for mounting said socket on a supporting structure in a predetermined spaced relation thereto and having a longitudinally extending internal bore, in substantially coaxial alignment with said aperture of said flange and withsaid socket, to receive one of said coaxial leads.

ORVILLE M. DUNNING. 

